Jesus, some shit suggestions here.
Corbin Dallas Multipass Easy solution. I always follow this progression after Junkyard.
Camp Hathor < Rail Crossing < Foundry < Core City < Expedition
With the addition of the ability to enter the Waterways, there are several cool places you can visit after Camp Hathor as well, peppering in visits and dungeons throughout your general progression till you hit the Expedition. This was how I played my first run through Underrail, and how I've played ever subsequent run. Everyone's different, but this always seemed the most natural progression for me, as the Opteonucleic Battery Blueprints are on the way to Camp Hathor, and it seemed logical to me to handle the minor issues of the station quickly before I went on to handling the big stuff. Following that, we head to Rail Crossing right away to find our missing compatriots, with a brief interlude at Foundry to get some resources before getting embroiled in the conflict there, and finally concluding at Core City, which is where it looked like all the action was going down considering the Faceless attack. If you follow this simple process, you'll have plenty of direction throughout the game, and it makes logical sense that your character would through the locations in this order.
As for the XP, Oddity is amazing, and hands down my favorite. No idea how people get so butthurt about Rathound Ears and Psi Beetle Brains no longer being claimable. As far as I know, you get little to no XP from killing them in classic once you get to a certain point, so doesn't that have the same effect? Regardless, if you ahve any questions feel free to ask.